The invention relates to a support for a commercial vehicle seating and operating unit, which is fastened to the support and comprises a rotatable bearing arrangement, thereby enabling rotation of the seating and operating unit about a vertical axis of rotation, the axis of rotation being spaced apart from the center of the seating and operating unit.
Commercial vehicles such as agricultural and industrial tractors, fork lift trucks and the like often have a plurality of seat positions, from which the vehicle may be controlled. This is necessary because the commercial vehicle performs different tasks, e.g. mowing, ploughing, digging or travelling, for which the person sitting in the seating and operating unit needs to adopt different positions to allow close monitoring of events. In particular, agricultural tractors often have to be driven in a forward or backward position of the seating or operating unit. Nowadays, seating units in commercial vehicles are often multi-functionally equipped in such a way that the driver sitting in the seat may guide the commercial vehicle by means of operating units disposed on the seat, in particular on the armrest of the seat. This means that the lines needed to connect the operating units to the commercial vehicle, such as electric cables, hydraulic or compressed-air lines, have to be run from the commercial vehicle to the appropriate points on the seating unit without hindering the rotatability of the seating unit and without the durability of the lines being impaired by rotation of the seat.
From document EP 0 369 951 B1 a seat for a commercial vehicle is known, which is rotatable between two opposite positions, the seat in one of these positions being disposed higher above the floor of the cab than in the other position. An operating unit for controlling the commercial vehicle is not provided on the seat.
In document DE 25 07 168 C2 a rotatable seating and operating unit of a commercial vehicle is described, which in various positions is locked against rotation by means of two locking units, a first locking unit being operated manually and the second locking unit being releasable only when the parking brake is engaged and at least one further condition ruling out driving of the vehicle is met. Details regarding the construction and installation of lines, which lead from the vehicle to the seating and operating unit, are not inferable from this document.
DE 199 61 249 A1 also describes a rotatably supported seat, an eccentric mechanism or crank mechanism being disposed between the driver's seat and the chassis and/or the cab floor of the commercial vehicle. By means of the mechanism solution disclosed in this document, the achievement of a radial swinging of the seat on a rotation of the seat relative to the steering wheel of more than 90°, e.g. of up to 360°, is possible and provided.
From EP 1 260 477 A1, moreover, an arrangement for rotatably supporting the driver's seat of a commercial vehicle is known, in which the bottom frame of the seat is rotatably supported by means of a downwardly directed rotatable journal in the bore of a bearing element that is raised off the cab floor. Fastened to the bearing element is a plate having a plurality of peripheral recesses, into which a locking bar disposed on the frame of the seat latches in various angular positions of the seat. The maximum rotatability of the seat is limited to a swivelling angle of approximately 90° by means of adjustable stops on the bottom frame of the seat, the adjustable stops interacting with stop faces on the plate. Situated on the armrest of the seat are control levers. How these are connected to the associated drives in the vehicle is however not apparent.